Sugar derivatives of 1,2-diamino-4,5-dimethyl-benzenes and process for the manufacture of same



Patented Apr. 1, 1941 FFICE SUGAR DERIVATIVES OF 1,2-nmnmo-4,s-

DIIVIETHYL-BENZENES PROCESS FOR.

THE MANUFACTURE OF SAFE Paul Karrer, Zurich, Switzerland, assignor to Hoffman-La Roche Inc., Nutley, N. 5., a corporation of New Jersey No Drawing. Application August 6, 1936, Serial Claims.

The derivatives of 1,2-diamino-4,5-'dimethylbenzene having a pentose or hexose radicle substituted in an amino group and consequently corresponding to the formulae 1130 NH.CH:(CHOH)4CH10H Inc NH;

The sugar derivatives of 1,2-diamino-4,5- dimethyl-benzene thus obtained may be converted into fiavines' by allowing alloxan to react with the solution obtained after the reduction.

It could not be foreseen that [3,4-dimethyL- phenyll-amino-pentoses or -hexoses would'allow themselves to be coupled with diazonium salts, because in other chemical reactions, for instance in nitrating, they are fOLIIld to be inert and behave differently from the simple aminesn It was moreover uncertain whether in the coupling 4 process the azo radicle would enter the orthoposition to the amino-sugar-group, as two other positions are likewise available.

Example 1 2 parts by weight of [3,4-dimethy1-phenylllaevo-arabamine melting at 123 C. (obtained by condensation and simultaneous hydrogenation of 1-amino-3,4-dimethyl-benzene and arabinose as shown in "Hel'vetica Chimica Acta, volume 18,

In Germany August 23, 1935 1935, page 1132) are dissolved in water and a diazo solution, obtained in the usual manner from 1 part by weight of p-nitraniline, is dropped in. A dark precipitate of the azo-dyestutf is immediately formed and is removed by suction and recrystallised. from dilute alcohol. pound is then dissolved in hot alcohol and hydrogenated in an autoclave with hydrogen and nickel at under 15 atmospheres pressure. After removal of the nickel catalyst there remains a colourless solution, containing the l-amino-2- arabinamino-4,5 -dimethyl-benzene. After acidifying, evaporating and treatment with alloxan, 6,7-dimethyl-9- [laevo-arabityll-iso alloxazine is obtained.

Example 2 [BA-dimethyl phenylldaevo arabinamine is coupled in aqueous solution with dlazotized 2,4- dinitraniline. The azo-dyestuff thus obtained is almost insoluble in water and 'is immediately precipitated in red-brown flakes. its reduction yields l-amino-2-arabinamino-4,5-dimethyl-benzene.

Example 3 [3,e-dimethyl phenyll-d ribamine (obtained by condensation and simultaneous hydrogenation Example 4 [3,4-dimethyl-phenyl]-d-arabamine is coupled in aqueous solution with diazotized aniline at a slightly acid reaction. One part by weight of the precipitated azo-dyestufi is dissolved after recrystallization from alcohol in parts by weight of boiling alcohol, then about one fifth part by volume of water is added and saturated sodiumhydrosulphite-solution dropped in until the redorange colour of the liquid has disappeared. By the addition of concentrated hydrochloric acid the reaction product is then made slightly acid to Congo paper and evaporated in vacuo. The residue is extracted with 20 parts by'weight of warm acetic acid whereby the greater part is dissolved.

By addin alloxan to this solution 6,7 dimethyl- 9-[d-arabityl]-iso-alloxazine is obtained.

The azo-com- 2. The process for the manufacture of 1-[dribityl-aminol -2-amino 4,5 dimethyl benzene, which consists in coupling [3,4-dimethyl-phenyl]- d-ribamine with a diazonium salt and treatingthe azo-dyestufl thus obtained with a. reducing agent.

3. The process for the manufacture of l-[dribityl-amino] -2-amino 4,5 dimethyl benzene, which consists in coupling [3,4-dimethyl-phenyli d-ribamine with diazotized p-nitraniline and treating the azo-dyestufl' thus obtained with zinc and acetic acid. I

4. The process for the manufacture of derivatives of 1,2-diamino-4,5-dimethy1-benzene o! the formula v O NH:

which consists in coupling 3,4-dimethyl-phenylamino sugars of the formula wherein n is a numeral selected from the group ing the am dyestufls thus obtained with reducing 2 agents.

PAUL KARRER. 

